I am a professor of social science methodoloy at the Faculty of Social Sciences of Utrecht University. My research interests are data quality in surveys and analysis models for complex data. My recent survey research focusses on nonresponse problems in surveys and interviewer effects. The complex data I work with are often multilevel or clustered data.

De Leeuw, E.D., Hox, J.J. & Scherpenzeel, A. (2010). Emulating Interviewers in an Online Survey: Experimental Manipulation of 'Do-Not-Know' over the Phone and on the Web. Proceedings of the Survey Research Methods Section of the Americal Statistical Association 2010 Alexandria: VA: American Statistical Association.

de Leeuw, E.D. & Hox, J.J. (1996). The effect of the interviewer on the decision to cooperate in a survey of the elderly. In S. Laaksonen (Eds.), International perspectives on nonrespons (pp. 46-52) (7 p.). Helsinki: Statistics Finland.